48 AGRICULTURE. 



animal or vegetable matter ; but when it does not 

 exceed twenty, the absorbent power is small, and 

 the vegetable matter deficient.* 



" 3d. Put the dried mass into a vase, with one 

 fourth of its own weight of clear water ; mix them 

 well together ; pour off the dirty water into a second 

 vase, and pour on to the residuum in the first vase as 

 much clean water as before ; stir the contents, and 

 continue this process until the water poured off is 

 as clear as that poured on the earth. What remains 

 in the first employed vase is sand, silicious or cal- 

 careous. 



11 3d. The dirty water collected in the second vase 

 will form a deposite, which, after pouring off the 

 water, must be dried, weighed, and calcined. On 

 weighing it after this process, the quantity lost will 

 show the portion of animal and vegetable mould con- 

 tained in the soil : and, 



" 4th. This calcined matter must then be carefully 

 pulverized and weighed, as also the first deposite of 

 sand, but without mixing them. To these apply, 

 separately, sulphuric acid, and what they respect- 

 ively lose in weight is the portion of calcareous or 

 aluminous earths contained in them. These last, 

 again, may be separated by soap ley, which dis- 

 solves them."t 



Here, then, is the light we wanted. By knowing 

 the disease, we find the cure. Clay and sand qual- 

 ify each other ; either of these will correct an ex- 

 cess of lime ; and magnesian earth, when saturated 

 with carbonic acid, becomes fertile. 



But entirely to alter the constitution of a soil, 

 whether by mechanical or other means, is a work 

 of time, labour, and expense, and little adapted to 

 the pecuniary circumstances of farmers in general. 



* See Davy's Elements. 



t This method of analyzing soils is that described by M. 

 Bosc, member of the Institute of France, &c., and recommend- 

 ed to French agriculturists. 



